VW AXQ 4.2 V8 Engine Specifications, Tuning, Problems

From 2002 to 2006, the AXQ engine was installed on the pre-styling version of the Volkswagen Touareg I SUV. This engine is famous for its reliable, albeit rather complex design.

And when buying of the used AXQ engine, the new owner can count on the fact that this engine will serve him for a very long time. The AXQ engine runs on gasoline and is capable of developing 310 hp.

It is also characterized by a really large volume – 4172 cm3. There are as many as 8 cylinders (they are arranged in a V-shape) and 40 valves (5 for each cylinder). However, we must admit that this engine consumes quite a lot of fuel – an average of 14.8 liters per 100 km.

The AXQ has an aluminum block with cast iron sleeves and a multiport fuel injection system. And the timing drive here is represented by one belt (and to replace it, you do not need to remove the internal combustion engine from its place) and two chains (they, in fact, play the role of phase regulators).

Applicability of AXQ engine

  • Touareg (2002-2006)
AXQ Engine Specifications
Volume (cm3)4172
Power (hp)310
Torque410 Nm
Timing driveBelt and 2 chains
Environmental classEuro 4
Fuel typeGasoline AI-95
ICE featuresNo
Supply systemDistribution injection
hydraulic liftersYes
Cylinder blockAluminum V8
cylinder headaluminum 40v
Cylinder diameter84.5 mm
piston stroke93 mm
Compression ratio11
Phase regulatorYes
Engine oil7.5 l 5W-30
Average resource280 000 km

Disadvantages and Problems of the AXQ engine

AXQ engine tensioners are demanding on oil pressure. If the level of this pressure is insufficient, then they will almost certainly fail. The likelihood of this increases even more with a sharp and sloppy ride on the part of the driver.

When using cheap, non-recommended oil (and also due to overheating of the AXQ engine), scoring may appear on the cylinder walls. In some cases, they can be eliminated with the help of special restorative compounds. However, there are situations when the only solution is a major overhaul.

In addition, this engine may have problems with the crankcase ventilation system.

Tuning prospects

The AXQ engine is controlled by a Bosch ME 7.1 unit. You can flash this block through the OBD-II connector, which, of course, simplifies the work of tuning masters.

  • Stage 1 chip tuning allows you to increase the power of this engine from 310 to 330 hp, and the torque from 410 to 445 Nm. It will certainly be a noticeable change.
  • After such a chip tuning, traction from the bottom will become more confident, and in general the internal combustion engine will be less thoughtful and will become more responsive to the driver’s actions.

In addition, this engine can be flashed to the Euro-2 standard (by removing the catalyst in parallel). This option is especially relevant if the diagnostics before chip tuning showed errors in the operation of this very catalyst.

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